It's hard to say not knowing what kind of hair you have (dry, oily, etc.), but in general people tend to over-condition their hair so if you want to use conditioner, its good to use it every other day.

In terms of combing, it's really dependent on your hair style. Only women with long hair really need to worry about combing it to prevent knotting.

In terms of shampoo and conditioner, going with some inexpensive and plant based it usually good.